// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_
#define NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_

#include <memory>

#include "base/macros.h"
#include "base/time/time.h"
#include "net/base/backoff_entry.h"
#include "net/base/net_export.h"

namespace base {
class Value;
class TickClock;
}

namespace net {

// Serialize or deserialize a BackoffEntry, so it can persist beyond the
// lifetime of the browser.
class NET_EXPORT BackoffEntrySerializer {
public:
    // Serializes the release time and failure count into a ListValue that can
    // later be passed to Deserialize to re-create the given BackoffEntry. The
    // Policy is not serialized, instead callers must pass an identical Policy*
    // when deserializing. |time_now| should be base::Time::Now(), except for
    // tests that want to simulate time changes. The release time TimeTicks will
    // be converted to an absolute timestamp, thus the time will continue counting
    // down even whilst the device is powered off, and will be partially
    // vulnerable to changes in the system clock time.
    static std::unique_ptr<base::Value> SerializeToValue(
        const BackoffEntry& entry,
        base::Time time_now);

    // Deserializes a ListValue back to a BackoffEntry. |policy| MUST be the same
    // Policy as the serialized entry had. |clock| may be NULL. Both |policy| and
    // |clock| (if not NULL) must enclose lifetime of the returned BackoffEntry.
    // |time_now| should be base::Time::Now(), except for tests that want to
    // simulate time changes. The absolute timestamp that was serialized will be
    // converted back to TimeTicks as best as possible. Returns NULL if
    // deserialization was unsuccessful.
    static std::unique_ptr<BackoffEntry> DeserializeFromValue(
        const base::Value& serialized,
        const BackoffEntry::Policy* policy,
        base::TickClock* clock,
        base::Time time_now);

private:
    DISALLOW_IMPLICIT_CONSTRUCTORS(BackoffEntrySerializer);
};

} // namespace net

#endif // NET_BASE_BACKOFF_ENTRY_SERIALIZER_H_
